.gitignore: Ignore the correct rename example binary

In e755186c we tried to introduce an example demonstrating
new virDomainRename API. Unfortunately, in the .gitignore we had
a different binary listed. It's 'rename' binary which we want git
to ignore, not 'test'.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

.gitignore

@@ -83,7 +83,7 @@
 /examples/domtop/domtop
 /examples/hellolibvirt/hellolibvirt
 /examples/openauth/openauth
-/examples/rename/test
+/examples/rename/rename
 /gnulib/lib/*
 /gnulib/m4/*
 /gnulib/tests/*